Question

Twenty identical articles are bought at 8 for Rs. 48 and all of them are sold at 5 for Rs. 37.50. Find the total number of articles bought and sold in order to gain Rs. 675.

Answer 1

Cost price of $8$ articles $=Rs48$
=> Cost price of $1$ article $=Rs\frac{48}{8}=6$
And Cost price of $8$ articles $=Rs6\times 20=Rs120$

Selling price of $5$ articles $=Rs37.50$
=> Selling price of $1$ article $=Rs\frac{37.5}{5}=Rs7.5$
And Selling price of $20$ articles $=Rs7.5\times 20=Rs150$

Now, profit on $20$ articles $=S.P.-C.P.=Rs150-Rs120=Rs30$

So, to gain $Rs675$, number of articles bought and sold $=\frac{20}{30}\times 675=450$